[sunseeker888]

. . . This wasn't built from scratch, but was actually a stereophonic Motorola radio which I stripped down and modified for use as a standalone power amp for headphones.

Tube rectified by a NOS EZ81, and Single Ended Motorola 6BM8's. I did briefly drive speakers off of it but the few watts per side didn't cut it with a 90dB/1w/1m speaker system.

So, Added a jack and we're good to go!

It sounds pretty nice overall, but will probably need a re-cap since there is a bit of hum with nothing playing. Not noticable on speakers, but when the speakers are strapped to your head it is!

 

[Nick 214]

What are the OPTs like?

 

[sunseeker888]

The left channel OPT is visible, but the other is underneath the chassis (? there's plenty of room on top!)

I would guess this amp's high-end tops out at about 15kHz. FM doesn't go much higher than that, and it's got OPT's. And it needs a re-cap!

But the realism is very cool. Thing SINGS.

 

[Nick 214]

Cool! Those OPTs are probably tapped for 8.... You may be able to tap them for 16. Do the math for your 325i's impedance...

 

[derekbmn]

The 6bm8 is a great sounding tube! Not real popular in the U.S. but quite well liked in Japan. Getting it recapped would be a wise thing to do.

Keep us updated.

 

[kansei]

What a coincidence, I just picked up a Monacor receiver off Craigslist for $15. It uses two 6bm8 tubes and has a 6ca4 rectifier. It ran OK for 30 minutes (yeah, needs tubes), and now it looks like the cap next to the transformer is about to blow up.

Now, I'm torn. I may put it on eBay for $50. Perhaps I will re-cap it and get new tubes and use it in my basement laboratory when I'm soldering. I'm also considering using the chassis for my Bijou build. Decisions...